Process for producing sticky polymers

ABSTRACT

A process for preventing agglomeration of sticky polymers in a polymerization system which comprises adding to said polymerization system about 0.3 to about 80 weight percent based on the weight of the final product of an inert particulate material having an organo-modified polydimethylsiloxane (OM-PDMS) surface coating thereon.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to sticky polymers and more particularlyto a process for preventing agglomeration of sticky polymers inpolymerization systems.

2. Description of the Prior Art

The introduction of high activity Ziegler-Natta catalyst systems haslead to the development of new polymerization processes based on gasphase reactors such as disclosed in U.S. Pat. No. 4,482,687 issued Nov.13, 1984. These processes offer many advantages over bulk monomer slurryprocesses or solvent processes. They are more economical and inherentlysafer in that they eliminate the need to handle and recover largequantities of solvent while advantageously providing low pressureprocess operation.

The versatility of the gas phase fluid bed reactor has contributed toits rapid acceptance. Alpha-olefins polymers produced in this type ofreactor cover a wide range of density, molecular weight distribution andmelt indexes. In fact new and better products have been synthesized ingas phase reactors because of the flexibility and adaptability of thegas phase reactor to a large spectrum of operating conditions.

The term "sticky polymer" is defined as a polymer, which, althoughparticulate at temperatures below the sticking or softening temperature,agglomerates at temperatures above the sticking or softeningtemperature. The term "sticking temperature", which, in the context ofthis specification, concerns the sticking temperature of particles ofpolymer in a fluidized or stirred bed, is defined as the temperature atwhich fluidization or stirring ceases due to excessive agglomeration ofparticles in the bed. The agglomeration may be spontaneous or occur onshort periods of settling.

By polymerization systems is meant those type reactors and systems whichare capable of producing and handling "sticky polymers". These caninclude fluidized bed reactors, stirred reactors, slurry reactors andgas-solid, gas-liquid-solid and liquid-solid phase polymerizationreactors and their post reactor receiving and handling units.

A polymer may be inherently sticky due to its chemical or mechanicalproperties or pass through a sticky phase during the production cycle.Sticky polymers are also referred to as non-free flowing polymersbecause of their tendency to compact into agglomerates of much largersize than the original particles. Polymers of this type show acceptablefluidity in a gas phase fluidized bed reactor; however, once motionceases, the additional mechanical force provided by the fluidizing gaspassing through the distributor plate is insufficient to break up theagglomerates which form and the bed will not refluidize. In addition instirred bed reactors particle agglomeration can seriously interfere withthe mechanical mixing action in the reactor. These polymers areclassified as those, which have a minimum bin opening for free flow atzero storage time of two feet and a minimum bin opening for free flow atstorage times of greater than five minutes of 4 to 8 feet or more.

Sticky polymers can also be defined by their bulk flow properties. Thisis called the Flow Function. On a scale of zero to infinity, the FlowFunction of free flowing materials such as dry sand is infinite. TheFlow Function of free flowing polymers is about 4 to 10, while the FlowFunction of non-free flowing or sticky polymers is about 1 to 3.

Although many variables influence the degree of stickiness of thepolymer resin, it is predominantly governed by the temperature and thecrystallinity of the resin. Higher temperatures of the resin increaseits stickiness while less crystalline products such as very low densitypolyethylene (VLDPE), ethylene/propylene monomer (EPM),ethylene/propylene/diene monomer (EPDM) and essentially amorphous orelastomeric polypropylene usually display a larger tendency toagglomerate to form larger particles.

Low pressure polymerizations in a gas phase reaction of olefin polymersusing transition metal catalysis are generally performed at temperaturesbelow 120° C. Where the higher levels of comonomers are used andcrystallinity levels are reduced below 30%, the melting or softeningtemperature of these olefin polymers can be close to the polymerizationtemperatures which are used. Under such conditions in either a fluidizedor stirred gas-solid phase reactor, stickiness of the olefin polymerparticles or granules becomes a problem. Ethylene copolymers usingpropylene, butene-1, and higher alpha comonomers are prone to stickinessproblems when their crystallinity is below 30% or densities less thanabout 910 kg/m³. The stickiness problem becomes even more critical withcopolymers of ethylene and propylene, and their diene terpolymers (EPMand EPDM, or EPRs) having a crystalline content less than 10%. Thepresence of diene further complicates the stabilization of the polymercomposition.

The stickiness problem in a fluidized bed or a gas-phase reactor can bereduced by the introduction of selected, fine-particle size, inorganicmaterials which act as a fluidization or flow aid. Certain grades ofcarbon black, clay and silica have been shown to be useful for thispurpose (see copending application Ser. No. 07/413,704 filed Sep. 28,1989 and which is assigned to a common assignee, now U.S. Pat. No.4,994,534. Further the treatment of alpha-olefin polymers with lowlevels of polydimethylsiloxane (PDMS) has been proposed as a means ofdiminishing adhesion of the polymer particles to themselves and to thereactor walls (see for example, European Patent application no. 0 254234 filed Jul. 17, 1987 and assigned to Mitsubishi Chemical IndustriesLimited and U.S. Pat. No. 4,675,368 issued Jun. 23, 1987).

However, the surface treatment of granular EPR with PDMS in aconcentration range of 0.01 to 5.0% by weight has not been found to beeffective in preventing sticking under fluidized bed conditions.Furthermore, there are processing difficulties (e.g., uniform coating ofdispersion without liquid binding) in directly treating the EPRs eitherin-situ or in post reaction in a continuous reaction with such PDMSbecause of their relative high viscosities.

The present invention relates to improvements not only in reducing thestickiness of polymer particles in polymerization systems but also inproviding an effective means for post reactor catalyst deactivation andstabilization without melt compounding. These improvements are obtainedwhen selected, fine-particle size, inorganic materials, such as carbonblack, clay, or silica, are surface treated with an organo modified (OM)polydimethylsiloxane (PDMS) and used in polymerization systems. Becausefunctional groups are present in the OM-PDMS, improved stabilization andcatalysts deactivation properties are imparted to the final products.

SUMMARY OF THE INVENTION

Broadly contemplated the present invention provides a process forpreventing agglomeration of sticky polymers in a polymerization systemwhich comprises adding to said polymerization system about 0.3 to about80 weight percent based on the weight of the final product of an inertparticulate material having a surface coating thereon of an OM-PDMS ofthe formula: ##STR1## wherein: R, may be the same or different, andrepresents phenyl or an alkyl group having from 1 to 4 carbon atoms;

R', represents hydrogen, or a straight or branched or cyclic alkyl chainhaving 5 to 50 carbon atoms;

R", may be the same or different and represents R or R'

R"' is alkylene, cycloaklyl, or alkoxy which can be substituted withhydroxy, amino, alkyl substituted amino, hydroxyl amino, phenol, alkylSubstituted phenol, alkyl substituted piperidinoxy and epoxy;

X=is an integer of 0 to <2000

Y=is an integer of 0 to <2000,

Z is an integer of 1 to 2000, with the proviso that the sum of (x+y+z)is greater than or equal to 4 and less than or equal to 2000, with thefurther proviso that the repeat units if they are present can be in anysequence, either random or non-random.

The organo-modified polydimethylsiloxane can be present on the inertparticulate material in an amount of about 0.02% to about 20% based onthe weight of said inert particulate material.

In a more limited aspect the present invention provides a method forpreventing agglomeration of sticky polymers produced in a fluidized bedreactor in the presence of a catalyst by conducting the polymerizationreaction in the presence of about 0.3 to about 80 weight percent,preferably about 5% to about 75% based on the weight of the finalproduct of the inert particulate material having a surface coatingthereon of the organo modified polydimethylsiloxane shown in the aboveformula.

The organo-modified polydimethylsiloxane can be present on the inertparticulate material in an amount of about 0.02% to about 20% based onthe weight of the inert particulate material.

In the above formula, R is preferably methyl, R' is preferably astraight or branched alkyl chain having 8 to 24 carbon atoms, R" ispreferably methyl or a straight or branched alkyl chain having 8 to 24carbon atoms.

When using the OM-PDMS materials of this invention, several improvementshave been noted and include (1) increased temperatures at which theresin bed can be fluidized without sticking problems for a givenpercentage of fluidization aid; (2) decreased concentration offluidization aid needed at a given reaction temperature; and/or (3) aviable means for catalyst deactivation and stabilization by activatingthe functionalities in a post reactor unit operation by contact withmoist nitrogen, for example. Another potential advantage of thisinvention is improved catalyst activity in the polymerization reaction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a typical gas fluidized bed reaction scheme forproducing sticky polymers.

DETAILED DESCRIPTION OF THE INVENTION

Although the process can be practiced in any polymerization system whichexperiences agglomeration of sticky polymers, the process is preferablyapplicable for preventing agglomeration of sticky polymers in afluidized bed reactor.

The fluidized bed reactor can be the one described in U.S. Pat. No.4,558,790. Other types of conventional reactors for the gas phaseproduction of, for example, polyethylene or ethylene copolymers andterpolymers can also be employed. At the start up, the bed is usuallymade up of polyethylene granular resin. During the course of thepolymerization, the bed comprises formed polymer particles, growingpolymer particles, and catalyst particles fluidized by polymerizable andmodifying gaseous components introduced at a flow rate or velocitysufficient to cause the particles to separate and act as a fluid. Thefluidizing gas is made up of the initial feed, make-up feed, and cycle(recycle) gas, i.e., monomer and, if desired, modifiers and/or an inertcarrier gas. The fluidizing gas can also be a halogen or other gas. Atypical cycle gas is comprised of ethylene, nitrogen, hydrogen,propylene, butene, or hexene monomers, diene monomers, either alone orin combination.

Examples of sticky polymers, which can be produced by subject processinclude ethylene/propylene rubbers and ethylene/propylene/dienetermonomer rubbers, polybutadiene rubbers, high ethylene contentpropylene/ethylene block copolymers, poly (1-butene) or essentiallyamorphous or elastomeric polypropylene (when produced under certainreaction conditions), very low density (low modulus) polyethylenes,ethylene/butene or hexene containing polymers,ethylene/propylene/ethylidenenorbornene, ethylene/propylene/hexadienepolymers of low density, ethylene/butene, ethylene/hexene,ethylene/propylene/butene, ethylene/propylene/hexene andethylene/butene/hexene polymers.

Subject process can be carried out in a batch or continuous mode, thelatter being preferred.

Characteristic of two types of resins which can be produced in subjectprocess are as follows:

One type of resin is an ethylene/propylene rubber containing 25 to 65percent, by weight, propylene. This material is sticky to the touch atreactor temperatures of 20° C. to 40° C. and has a severe tendency toagglomerate when allowed to settle for periods of more than two to fiveminutes. Another sticky resin is an ethylene/butene copolymer producedat reactor temperatures of 50° C. to 80° C. at density levels of 880 to905 kilograms per cubic meter and melt index levels of 1 to 20 andchlorinated or chlorosulfonated after being produced in the fluidizedbed reactor.

The inert particulate material employed according to the presentinvention are materials which are substantially chemically inert to thereaction. Examples of inert particulate materials include carbon black,silica, talc, clays and other like materials. Carbon blacks are thepreferred materials. The carbon black materials employed have a primaryparticle size of about 1 to 100 nano meters and an average size ofaggregate (primary structure) of about 0.01 to about 10 microns. Thespecific surface area of the carbon black is about 30 to 1,500 m² /gmand display a dibutylphthalate (DBP) absorption of about 10 to about 700cc/100 grams.

The silicas which can be employed are amorphous silicas having a primaryparticle size of about 5 to 50 nanometers and an average size ofaggregate of about 0.1 to about 10 microns. The average size ofagglomerates of silica is about 2 to about 120 microns. The silicasemployed have a specific surface area of about 50 to 500 m² /gm and adibutylphthalate (DBP) absorption of about 100 to 400 cc/100 grams.

Non-aggregated silicas, clays, talc, and other powdery materials canalso be employed according to the present invention and they can have anaverage particle size of about 0.01 to about 10 microns and a specificsurface area of about 2 to 350 m² /gm. They exhibit oil absorption ofabout 20 to about 300 gms per 100 gms.

It is preferred that both amorphous and non-aggregated silicas as wellas talc should be substantially calcined to drive out chemisorbed waterand/or hydroxyl groups in them. This calcination should be done beforethese materials are surface treated with an OM-PDMS. A propercalcination temperature would be in the range of 500° C. to 900° C.,preferably 700° to 800° C.

The coating which is applied to the inert particulate material isformulated from an organo-modified polydimethylsiloxane of the formula:##STR2## wherein: R, may be the same or different represents phenyl oran alkyl group having from 1 to 4 carbon atoms;

R', represents hydrogen, or a straight or branched or cyclic alkyl chainhaving 5 to 50 carbon atoms;

R", may be the same or different represents R or R

R"' is alkylene, cycloalkyl or alkoxy which can be substituted withhydroxy, amino, alkyl substituted amino, hydroxyl amino, phenol, alkylsubstituted phenyl, and epoxy.

X=is an integer of 0 to <2000

Y=is an integer of 0 to <2000,

Z=is an integer of 1 to 2000, with the proviso that the sum of (x+y+z)is greater than or equal to 4 and less than or equal to 2000, with thefurther proviso that the repeat units if they are present can be in anysequence, either random or non-random.

Examples of organo modified polydimethylsiloxanes which can be employedin the present invention include 3-hydroxypropyl modifiedpolydimethylsiloxane, propylglycidyl ether modified PDMS;propoxypropanediol modified PDMS, propylamine modified PDMS,di-2-hydroxy ethyl propyl amino PDMS ethyl cyclohexane monoxide modifiedPDMS, propyl-3-(3,5-di-tert. butyl-4-hydroxy phenyl) propionate,modified PDMS propyl-3-(3,5-di-tert, butyl-4-hydroxy phenyl) modifiedPDMS propyl-3-(2,2,6,6-tetramethyl-4-piperidinoxy) modified PDMSoctyl-8-(2,2,6,6-tetramethyl-4-piperidinoxy) modified PDMS,(2,2,6,6-tetra methyl-4 piperidinoxy) modified PDMS,propyl-3-(1,2,2,6,6-pentamethyl-4-piperidinoxy) modified PDMS.

In general the coating can be applied to the solid particulate materialby dissolving the OM-PDMS in a suitable solvent such as methylenechloride and thereafter adding the inert material to the solution toform a slurry. The solvent can then be evaporated to leave a coating ofthe PDMS over the inert material. Alternatively, the OM-PDMS solutioncan be sprayed on to the inert particulate material. In a furtherprocedure an aqueous dispersion of the OM-PDMS can be formed and appliedto the inert particulate material either by the spraying or slurryprocedure described above. The water can be removed by conventionalprocedures. Other conventional means of surface treatment can beemployed as known in the art.

The coating is present on the surface of inert particulate material inan amount of 0.02%, to about 20% preferably about 1% to about 10% basedon the weight of the inert particulate material.

The amount of inert particulate material utilized generally depends onthe type of material utilized and the type of polymer produced. Whenutilizing carbon black or amorphous silicas as the inert material, theycan be employed in amounts of about 0.3 to about 70% by weightpreferably about 5% to about 65% based on the weight of the finalproduct produced (weight of polymer plus weight of inert particulate andweight of OM-PDMS and other additives or residues). When non-aggregatedsilicas, clays, talc, or other powdery materials or mixture thereof areemployed as the inert particulate material, the amount can range fromabout 0.3 to about 80% based on the weight of the final productpreferably about 12% to 75% by weight.

The coated inert particulate materials can be directly introduced intothe reactor, preferably at the bottom of the reactor or to the recycleline directed into the bottom of the reactor. It is preferred to treatthe coated inert particulate material prior to entry into the reactor toremove traces of moisture and oxygen. This can be accomplished bypurging the material with nitrogen gas, and heating by conventionalprocedures.

A fluidized bed reaction system which is particularly suited toproduction of polyolefin resin by the practice of the process of thepresent invention is illustrated in the drawing. With reference theretoand particularly to FIG. 1, the reactor 10 comprises a reaction zone 12and a velocity reduction zone 14.

In general, the height to diameter ratio of the reaction zone can varyin the range of about 2.7:1 to about 5:1. The range, of course, can varyto larger or smaller ratios and depends upon the desired productioncapacity. The cross-sectional area of the velocity reduction zone 14 istypically within the range of about 2.5 to about 2.9 multiplied by thecross-sectional area of the reaction zone 12.

The reaction zone 12 includes a bed of growing polymer particles, formedpolymer particles and a minor amount of catalyst all fluidized by thecontinuous flow of polymerizable and modifying gaseous components in theform of make-up feed and recycle fluid through the reaction zone. Tomaintain a viable fluidized bed, the superficial gas velocity (SGV)through the bed must exceed the minimum flow required for fluidizationwhich is typically from about 0.2 to about 0.8 ft/sec depending on theaverage particle size of the product. Preferably the SGV is at least 1.0ft/sec above the minimum flow for fluidization of from about 1.2 toabout 6.0 ft/sec. Ordinarily, the SGV will not exceed 6.0 ft/sec and itis usually no more than 5.5 ft/sec.

Particles in the bed help to prevent the formation of localized "hotspots" and to entrap and distribute the particulate catalyst through thereaction zone. Accordingly, on start up, the reactor is charged with abase of particulate polymer particles before gas flow is initiated. Suchparticles may be the same as the polymer to be formed or different. Whendifferent, they are withdrawn with the desired newly formed polymerparticles as the first product. Eventually, a fluidized bed consistingof desired polymer particles supplants the start-up bed.

The catalysts used are often sensitive to oxygen, thus the catalyst usedto produce polymer in the fluidized bed is preferably stored in areservoir 16 under a blanket of a gas which is inert to the storedmaterial, such as nitrogen or argon.

Fluidization is achieved by a high rate of fluid recycle to and throughthe bed, typically on the order of about 50 to about 150 times the rateof feed of make-up fluid. This high rate of recycle provides therequisite superficial gas velocity necessary to maintain the fluidizedbed. The fluidized bed has the general appearance of a dense mass ofindividually moving particles as created by the percolation of gasthrough the bed. The pressure drop through the bed is equal to orslightly greater than the weight of the bed divided by thecross-sectional area. It is thus dependent on the geometry of thereactor.

Make-up fluid can be fed at point 18 via recycle line 22 although it isalso possible to introduce make up fluid between heat exchanger 24 andvelocity reduction zone 14 in recycle line 22. The composition of therecycle stream is measured by a gas analyzer 21 and the composition andamount of the make-up stream is then adjusted accordingly to maintain anessentially steady state gaseous composition within the reaction zone.

The gas analyzer is a conventional gas analyzer which operates inconventional manner to indicate recycle stream composition and which isadapted to regulate the feed and is commercially available from a widevariety of sources. The gas analyzer 21 can be positioned to receive gasfrom a point between the velocity reduction zone 14 and the dispenser38, preferably after the compressor 30.

To ensure complete fluidization, the recycle stream and, where desired,part of the make-up stream are returned through recycle line 22 to thereactor at point 26 below the bed preferably there is a gas distributorplate 28 above the point of return to aid in fluidizing the beduniformly and to support the solid particles prior to start-up or whenthe system is shut down. The stream passing upwardly through the bedabsorbs the heat of reaction generated by the polymerization reaction.

The portion of the gaseous stream flowing through the fluidized bedwhich did not react in the bed becomes the recycle stream which leavesthe reaction zone 12 and passes into a velocity reduction zone 14 abovethe bed where a major portion of the entrained particles drop back intothe bed thereby reducing solid particle carryover.

The recycle stream exiting the compressor is then returned to thereactor at its base 26 and thence to the fluidized bed through a gasdistributor plate 28. A fluid flow deflector 32 is preferably installedat the inlet to the reactor to prevent contained polymer particles fromsettling out and agglomerating into a solid mass and to maintainentrained or to re-entrain any liquid or solid particles which maysettle out or become disentrained.

The fluid flow deflector, comprises an annular disc supported at a standoff distance above the reactor inlet 26 by the spacers 32a and dividesthe entering recycle stream into a central upward flow stream and anupward peripheral annular flow stream along the lower side walls of thereactor. The flow streams mix and then pass through protective screen27, the holes or ports 29 of the distributor plate 28 and the angle caps36a and 36b, secured to the upper surface of the distributor plate, andeventually into the fluidized bed.

The central upward flow stream in the mixing chamber 26a assists in theentrainment of liquid droplets in the bottom head or mixing chamber andin carrying the entrained liquid to the fluidized bed section during acondensing mode of reactor operation. The peripheral flow assists inminimizing build-up of solid particles in the bottom head because itsweeps the inner surfaces of the reactor walls. The peripheral flow alsocontributes to the re-atomization and re-entrainment of any liquid whichmay be disentrained at the walls or accumulate at the bottom of thediffuser mixing chamber, particularly with a high level of liquid in therecycle stream. The annular deflector means 32, which provides bothcentral upward and outer peripheral flow in the mixing chamber, permitsa reactor to be operated without the problems of liquid flooding orexcessive build up of solids at the bottom of the reactor.

The temperature of the bed is basically dependent on three factors: (1)the rate of catalyst injection which controls the rate of polymerizationand the attendant rate of heat generation; (2) the temperature of thegas recycle stream and (3) the volume of the recycle stream passingthrough the fluidized bed. Of course, the amount of liquid introducedinto the bed either with the recycle stream and/or by separateintroduction also affects the temperature since this liquid vaporizes inthe bed and serves to reduce the temperature. Normally the rate ofcatalyst injection is used to control the rate of polymer production.The temperature of the bed is controlled at an essentially constanttemperature under steady state conditions by constantly removing theheat of reaction. By "steady state" is meant a state of operation wherethere is no change in the system with time. Thus, the amount of heatgenerated in the process is balanced by the amount of heat being removedand the total quantity of material entering the system is balanced bythe amount of material being removed. As a result, the temperature,pressure, and composition at any given point in the system is notchanging with time. No noticeable temperature gradient appears to existwithin the upper portion of the bed. A temperature gradient will existin the bottom of the bed in a layer or region extending above thedistributor plate, e.g., for about 6 to about 12 inches, as a result ofthe difference between the temperature of the inlet fluid andtemperature of the remainder of the bed. However, in the upper portionor region above this bottom layer, the temperature of the bed isessentially constant at the maximum desired temperature.

Good gas distribution plays an important role in the efficient operationof the reactor. The fluidized bed contains growing and formedparticulate polymer particles, as well as catalyst particles. As thepolymer particles are hot and possible active, they must be preventedfrom settling, for if a quiescent mass is allowed to exist, any activecatalyst present will continue to react and can cause fusion of thepolymer particles resulting, in an extreme case, in the formation of asolid mass in the reactor which can only be removed with a greatdifficulty and at the expense of an extended downtime. Since thefluidized bed in a typical commercial size reactor may contain manythousand pounds of solids at any given time, the removal of a solid massof this size would require a substantial effort. Diffusing recycle fluidthrough the bed at a rate sufficient to maintain fluidization throughoutthe bed is, therefore, essential.

Any fluid inert to the catalyst and reactants and which, if a liquid,will volatilize under the conditions present in the fluidized bed, canalso be present in the recycle stream. Other materials, such as catalystactivator compounds, if utilized are preferably added to the reactionsystem downstream from compressor 30. Thus the materials may be fed intothe recycle system from dispenser 38 through line 40 as shown in FIG. 1.

The fluid bed reactor may be operated at pressures of up to about 1000psig. The reactor is preferably operated at a pressure of from about 250to about 500 psig, with operation at the higher pressures in such rangesfavoring heat transfer since an increase in pressure increases the unitvolume heat capacity of the gas.

The catalyst which is preferably a transition metal catalyst is injectedintermittently or continuously into the bed at a desired rate at a point42 which is above the distributor plate 28. Preferably, the catalyst isinjected at a point in the bed where good mixing with polymer particlesoccurs. Injecting the catalyst at a point above the distributor plate isan important feature for satisfactory operation of a fluidized bedpolymerization reactor. Since catalysts are highly active, injection ofthe catalyst into the area below the distributor plate may causepolymerization to begin there and eventually cause plugging of thedistributor plate. Injection into the fluidized bed aids in distributingthe catalyst throughout the bed and tends to preclude the formation oflocalized spots of high catalyst concentration which may result in theformation of "hot spots". Injection of the catalyst into the reactor ispreferably carried out in the lower portion of the fluidized bed toprovide uniform distribution and to minimize catalyst carryover into therecycle line where polymerization may begin and plugging of the recycleline and heat exchanger may eventually occur.

The coated inert particulate materials are introduced into the reactorfrom Vessel 31 through line 31a together with inert gas or alternativelythrough 31b where it is joined with recycle line 22.

A gas which is inert to the catalyst, such as nitrogen or argon, ispreferably used to carry the catalyst into the bed.

The rate of polymer production in the bed depends on the rate ofcatalyst injection and the concentration of monomer(s) in the recyclestream. The production rate is conveniently controlled by simplyadjusting the rate of catalyst injection.

Under a given set of operating conditions, the fluidized bed ismaintained at essentially a constant height by withdrawing a portion ofthe bed as product at the rate of formation of the particular polymerproduct. Complete instrumentation of both the fluidized bed and therecycle stream cooling system is, of course, useful to detect anytemperature change in the bed so as to enable either the operator or aconventional automatic control system to make a suitable adjustment inthe temperature of the recycle stream or adjust the rate of catalystinjection.

On discharge of particulate polymer product from the reactor 10, it isdesirable, and preferable, to separate fluid from the product and toreturn the fluid to the recycle line 22. There are numerous ways knownto the art to accomplish this. One system is shown in the drawings.Thus, fluid and product leave the reactor 10 at point 44 and enter theproduct discharge tank 46 through a valve 48 which is designed to haveminimum restriction to flow when opened, e.g., a ball valve. Positionedabove and below product discharge tank 46 are conventional valves 50, 52with the latter being adapted to provide passage of product into theproduct surge tank 54. The product surge tank 54 has venting meansillustrated by line 56 and gas entry means illustrated by line 58. Alsopositioned at the base of product surge tank 54 is a discharge valve 60which, when in the open position, discharges product for conveying tostorage. Valve 50, when in the open position, releases fluid to surgetank 62. Fluid from product discharge tank 46 is directed through afilter 64 and thence through surge tank 62, a compressor 66 and intorecycle line 22 through line 68.

In a typical mode of operation, valve 48 is open and valves 50, 52 arein a closed position. Product and fluid enter product discharge tank 46.Valve 48 closes and the product is allowed to settle in productdischarge tank 46. Valve 50 is then opened permitting fluid to flow fromproduct discharge tank 46 to surge tank 62 from which it is continuallycompressed back into recycle line 22. Valve 50 is then closed and valve52 is opened and product in the product discharge tank 46 flows into theproduct surge tank 54. Valve 52 is then closed. The product is purgedwith inert gas preferably nitrogen, which enters the product surge tank54 through line 58 and is vented through line 56. Product is thendischarged from product surge tank 54 through valve 60 and conveyedthrough line 20 to storage.

The particular timing sequence of the valves is accomplished by the useof conventional programmable controllers which are well known in theart. The valves can be kept substantially free of agglomerated particlesby installation of means for directing a stream of gas periodicallythrough the valves and back to the reactor.

The following Examples will illustrate the present invention.

Examples 1 to 10 illustrate the improvements in reducing tack orstickiness of polymer particles in a non-reacting gas fluidized bed whenan inert particulate material treated with a selected OM-PDMS was used.Instead of directly evaluating the treated inert particulate material inreacting gas fluidized bed where polymerization reactions take place,the treated material was first evaluated in this non-reacting bed tosimulate and determine how much of the polymer stickiness could bereduced when the treated inert particulate material was used. Theeffects of a treated inert particulate material on fluidized bed reactoroperation and the critical content of the material in EPDM polymerproduced are comparatively illustrated in Examples 11 and 12.

As shown in the following Examples 1 to 10, the benefits of using atreated inert particulate material over using a neat (or untreated)inert particulate material were determined by measuring and comparingthe Maximum Allowable Bed Temperatures (MABTs) and Channelling BedTemperatures (CBTs) of the gas fluidized bed, both to be defined below.The reason for this is that within the range of the glass transitiontemperature and melting temperature of a given polymer, the degree ofits stickiness increases with the increase of its temperature.

The MABT is defined as the temperature of the gas fluidized bed at whichstagnant (or "dead") zones start to form in the bed due to theagglomeration of polymer resin. If the bed temperature is kept below theMABT, the bed maintains the desirable bubbling flow without having anysevere agglomeration of polymer resin or formation of dead zones.

When the bed temperature is raised further from the MABT, the polymerresin becomes stickier, resulting in the formation of small stagnantzones caused by resin agglomeration. The stagnant zones grow up withtime particularly near the corner of the distributor plate and bedwalls. Eventually several small channels (or "rat holes") are formed atthe lower portion of the fluidized bed, while the upper portion of thebed is still being fluidized in a bubbling flow regime. A furtherincrease of the bed temperature makes the whole bed collapse within ashort period of time. This results in a complete channeling flow withone or multiple channels formed from the bottom to the top of the bed.The gas bypasses through the channels. When the complete defluidizationoccurs, the pressure drop across the bed decreases sharply. The CBT isdefined as the bed temperature at which there form channels in the majorportion of the fluidized bed, typically about 50% of the bed by volume.It was possible to visually observe all these phenomena because thefluidized bed was constructed with Plexiglas, a transparent material.

The MABT and CBT of an EPR, measured in a gas fluidized bed, dependamong other things upon the stickiness of the EPR in the fluidizingenvironment, the type of inert particulate materials and their addedamounts, the type of OM-PDMS and their added amounts, the superficialvelocity of the fluidizing gas, and the type of distributor platesemployed in the fluidized bed. For the evaluation of each OM-PDMS fluid,therefore, the fluidization tests were performed by fixing all otherindependent variables except the type and added amount of each fluid.

Since the degree of stickiness of a given polymer resin increases withthe increase of its temperature, the benefits of a surface treatment ofan inert particulate material with an OM-PDMS over an untreated inertparticulate material are determined by comparing the MABT and CBTobtained with each material. In other words, if a surface treated inertparticulate material gives higher MABT and CBT than the neat inertparticulate material, the treated one is more efficient in preventingthe polymer resin from being agglomerated by reducing the surfacestickiness of the polymer particles.

EXAMPLE 1

This example demonstrates measurement of the MABT and CBT of an EPMgranular resin when a neat inert particulate material was used. Thenumber average molecular weight of the EPM polymer was 39,000 measuredby Size Exclusion Chromatography (SEC). The propylene content in thepolymer was 32.1% by weight measured by Nuclear Magnetic Resonance(NMR). The granular resin had a weight average particle size of 0.043inches (1.092 mm). The neat inert particulate material used for the testwas "CD-9002" carbon black produced by Columbian Chemicals Company.

This EPM granular resin (1,960 grams) was mixed with the untreatedcarbon black powder (40 grams) in a glass jar. The average value of theuntreated carbon black concentration in the final mixture was 2% byweight. The glass jar was rolled on a roller at room temperature forapproximately 15 hours to provide uniform mixing of the materials and toprovide uniform coating of the resin surface with the carbon black. Thismixture was introduced into a Plexiglas fluidized bed. The innerdiameter and height of the fluidized bed were 6.5 inches (16.51 cm) and6 feet (1.83 m), respectively. The distributor plate employed for thistest was a uniformly porous one which consisted of one perforatedstainless steel plate and three layers of fine mesh screens laminated onthe obverse of the perforated plate. The diameter of each perforationwas 3/64 inches (1.191 mm). The perforations had a triangular matrixwith a pitch of 5/32 inches (3.97 mm). The fine mesh screens effectivelyprevented the fines in the resin from sifting into the bottom head ofthe fluidized bed. Furthermore, the pressure drop across the distributorplate was high enough (i.e., higher than 25% of the pressure drop acrossthe fluidized bed) to provide a uniform gas flow through the distributorplate. Plant compressed air, after its pressure was properly regulated,was used as the fluidizing gas. An electrical heater with a controllerwas used to heat up the compressed air which, in turn, controlled thetemperature of the fluidized bed or resin. A flow meter and a valve werelocated at the upstream of the heater, which gave the volume flow rateof air at room temperature. To maintain the superficial gas velocity inthe fluidized bed at 2.3 ft/s (0.701 m/s) at all bed temperatures, itwas necessary to adjust the valve and flow meter reading at eachtemperature level to compensate for the expansion of gas with anincrease of temperature. The pressure and temperature of the fluidizedbed were measured by using a manometer and a thermocouple, respectively.The pressure in the fluidized bed was slightly higher than theatmospheric pressure.

The test started at room temperature. The settled bed height was 8.5inches. When the superficial gas velocity was set at 2.3 ft/s, a verysmall amount, if any, of the carbon black was entrained during the first2 to 3 seconds and there was no entrainment thereafter. The material wasfluidizing very well in a bubbling flow regime at that gas velocity withan average value of the fluidized bed height of about 14.5 inches. Thefluidized bed was carefully observed to ensure that there were no deadzones at the gas velocity. The set point of the heater controller wasincreased to raise the temperature of the fluidized bed. The typicalincrement of the set point was about 3° C. to 5° C. It took about 15minutes for the fluidized bed to reach a steady state at the higherlevel of temperature. Once the bed reached a steady state at the highertemperature, the air flow rate was adjusted to maintain the samesuperficial gas velocity and the bed was operated for at least 30minutes. During this period of time, the bed was carefully observed todetermine whether there occurred any severe agglomeration of resin orformation of dead zones.

When the fluidized bed reached a steady state at a temperature of 45° C.and the same superficial gas velocity, there first formed a small deadzone at one corner of the distributor plate and the bed wall. As timepassed, the size of the first dead zone increased and another small deadzone was formed on the other side of the corner. Visual observationthrough the Plexiglas wall suggested that each dead zone had a shapesimilar to a triangle. Both dead zones grew up to about 0.5 inches inboth base and height for the first 15 minutes and stayed there for thenext 15 minutes. Therefore, the MABT of this fluidized bed was 45° C.

When the temperature was raised above the MABT by about 3° C., the sizeof each dead zone was increased in both base and height, and other deadzones were also formed and grew up at different locations of the corner.Eventually, all the resin in the whole corner became stagnant withmultiple channels. When the bed reached a steady rate, the height of thedead zone was observed to vary from 0.5 inches to 1.0 inch dependingupon the locations. A further increase of the bed temperature by 3° C.rapidly increased the height of the dead zone. When the bed temperaturereached a steady state, the stagnant portion of the bed was channellingseverely and its volume reached up to about 50% of the total bed volume.Most of the air bypassed through the channels and the resin above thestagnant layer was still fluidizing in a bubbling flow regime.Therefore, the CBT of this fluidized bed was 51° C.

The following Examples 2 to 4 illustrate not only the benefits of asurface treatment of the inert particulate material with an OM-PDMS butalso the effect of its concentration on MABT and CBT. The samefluidization test facilities, test method, test conditions, EPM granularresin, and inert particulate material as in Example 1 were used for thetests shown in these examples. The inert particulate material, however,was now treated with a selected OM-PDMS before the material was mixedwith the EPM granular resin to provide a test sample. Since the volumeof the OM-PDMS is substantially smaller than the volume of the carbonblack to be treated, the OM-PDMS was dissolved in a solvent, the volumeof which was big enough to make a carbon black slurry with. Methylenechloride was used as the solvent. The solvent was then evaporated atroom temperature, leaving the carbon black uniformally treated with theOM-PDMS. Normally, the treated carbon black was caked up, requiring asubsequent pulverization to make a powder to facilitate the dispersionof the carbon black on the surface of EPM resin. Either a mortar andpestle or a blender can be used for the pulverization of such smallamount of caked carbon black. A blender manufactured by Waring was usedto pulverize the treated carbon blacks used in these examples.

EXAMPLE 2

The OM-PDMS used to treat the same carbon black as in Example 1 was a3-hydroxypropyl PDMS and in the formula indicated previously, X=15, Y=0and Z=5. R, R" are methyl, R"' is (CH₂)₃ OH and is referred to asOM-PDMS-A hereinafter.

Forty grams of the carbon black was treated with 2 grams of OM-PDMS-A.The total weight of the final sample prepared for the test was 2,000grams: 1,958 grams EPM, 40 grams carbon black (2% by weight), and 2grams OM-PDMS-A (0.1% by weight).

The MABT and CBT obtained with this sample were 52° C. and 63° C.,respectively. The benefit of this treatment was a 7° C. increase in MABTand a 12° C. increase in CBT over the same amount of neat carbon blackshown in Example 1. These results clearly show that the treatment madethe carbon black more efficient in preventing the polymer resin frombeing agglomerated by reducing the surface stickiness of the polymerparticles. In other words, the OM-PDMS-A provided the carbon black witha synergistic effect (or synergism).

EXAMPLE 3

Forty grams of CD-9002 carbon black was treated with 4 grams ofOM-PDMS-A. The total weight of the final sample prepared for the testwas 2,000 gram: 1,956 gram EPM, 40 gram carbon black (2% by weight), and4 gram OM-PDMS-A (0.2% by weight).

The MABT and CBT obtained with this sample were 63° C. and 69° C.,respectively. When the concentration of the OM-PDMS-A in the carbonblack was increased, a higher synergistic effect was obtained.

EXAMPLE 4

Since the synergistic effect increased with the increase of theOM-PDMS-A concentration in the carbon black, the test sample was made sothat it consisted of 1,950 grams EPM, 40 grams CD-9002 (2% by weight),and 10 grams OM-PDMS-A (0.5% by weight).

The MABT and CBT obtained with this sample were 63° C. and 77° C.,respectively. When these results were compared with those in Example 3,it was seen that a further increase of OM-PDMS-A concentration in thecarbon black did not give any substantially higher synergistic effect.In fact, the MABTs were the same. It appeared that there exists anoptimum concentration of this OM-PDMS-A in this carbon black.

EXAMPLE 5

This example illustrates that not all OM-PDMSs give the synergisticeffect. The OM-PDMS used in this example is "SILWETT L-77", a commercialproduct of Union Carbide Chemicals and Plastics Company Inc., which isnot included in the OM-PDMS structural formula. The same fluidizationtest facilities, test method, test conditions, EPM granular resin, inertparticulate material, and treatment method as in Example 2 were used forthe test. The test sample consisted of 1,956 grams EPM, 40 grams CD-9002carbon black (2% by weight), and 4 grams "SILWETT L-77" (0.2% byweight).

The MABT and CBT obtained with this sample were 45° C. and 51° C.,respectively. When these results were compared with those in Examples 1and 3, it was seen that "SILWETT L-77" did not provide the synergism.

The following Examples 6 to 10 illustrate that similar benefits wereobtained regardless of the types of EPM polymer and inert particulatematerial. The EPM resin used for these examples had a number averagemolecular weight of 31,000 measured by SEC, a weight average particlesize of 0.039 inches (0.991 mm), and a propylene content in the polymerof 27.3% by weight measured by NMR. The inert particulate material usedfor these examples was "Polyfil-90" which was a calcined claycommercially produced by J. M. Huber Corporation. The OM-PDMS-A was usedto treat the inert Particulate material for these examples.

EXAMPLE 6

To prepare a test sample, an EPM granular resin of 1,900 grams and anuntreated "Polyfil-90" calcined clay of 100 grams were mixed using thesame procedures as in Example 1. The average concentration of the clayin the mixture was 5% by weight.

The same non-reacting fluidization test facilities as in Example 1 wereutilized. The same test procedures as in Example 1 were employed,including a superficial gas velocity of 2.3 ft/s (0.701 m/s).

The MABT and CBT obtained with this sample were 64° C. and 67° C.,respectively.

EXAMPLE 7

Employing the same treatment method as in Examples 2 to 5, 100 grams of"Polyfil-90" were treated with 2 grams of the OM-PDMS-A. The test sampleconsisted of 1,898 grams EPM, 100 grams "Polyfil-90" (5% by weight), and2 grams OM-PDMS-A (0.1% by weight).

The measured MABT and CBT of this sample were 75° C. and 79° C.,respectively. When these values were compared with those in Example 6,it was apparent that the treatment gave a substantial synergisticeffect: 11° C. increase of MABT and 12° C. increase of CBT.

EXAMPLE 8

One hundred grams of "Polyfil-90" was treated with 4 grams of theOM-PDMS-A using the same treatment method as in Example 7. The testsample consisted of 1,896 grams EPM, 100 grams "Polyfil-90" (5% byweight), and 4 grams OM-PDMS-A (0.2% by weight).

The test results showed that the MABT and CBT of this sample were 79° C.and 84° C., respectively. When the concentration of the OM-PDMS-A in thecalcined clay was increased, a higher synergistic effect was obtained:15° C. and 17° C. increases of MABT and CBT, respectively.

EXAMPLE 9

Since the synergism was enhanced with the increase of the OM-PDMS-Aconcentration in the calcined clay, the test sample was made in a waythat it consisted of 1,892 grams EPM, 100 grams "Polyfil-90" (5% byweight), and 8 grams of OM-PDMS-A (0.4% by weight).

The measured MABT and CBT of this sample were 83° C. and 88° C.,respectively. Comparing these values with those in Example 8, it wasapparent that the synergistic effect was still increasing with theincrease of the OM-PDMS-A concentration in the calcined clay: another 4°C. increase of both MABT and CBT.

EXAMPLE 10

To determine whether the synergism would be raised further when theconcentration of the OM-PDMS-A was increased even further, the testsample was provided in a way that it consisted of 1,888 grams EPM, 100grams "Polyfil-90" (5% by weight), and 12 grams OM-PDMS-A (0.6% byweight).

The test results showed that the MABT and CBT of this sample were 83° C.and 87° C., respectively. No further enhanced synergistic effect wasobtained when this large amount of the OM-PDMS-A was used to treat thecalcined clay. It appeared that there exists an optimum concentration ofthis OM-PDMS-A in this clay.

The following Examples 11 and 12 illustrate the benefits that areobtained when an inert particulate material treated with an OM-PDMS isused in a gas-phase fluidized bed reactor to produce an EPDM granularresin. N-650 carbon black powder is used as an inert particulatematerial and OM-PDMS-A is used as an OM-PDMS. This N-650 rubber gradecarbon black is the one commercially produced by Columbian ChemicalsCompany. The amounts of propylene and ENB incorporated in the polymersare measured by Nuclear Magnetic Resonance (NMR) technique. The amountsof the carbon black incorporated on the polymer particles are determinedby Thermogravimetric Analysis (TGA).

EXAMPLE 11 Production of EPDM with Untreated N-650 Carbon Black

The fluidized bed pilot plant reactor has an inner diameter of about 14inches (35.56 cm). The superficial gas velocity in the fluidized bedreactor is typically maintained at about 2.5 ft/s (0.762 m/s); thefluidized bed height at about 5.5 feet (1.68 m); and the reactortemperature at 70° C.

Before the N-650 carbon black powder is introduced into the fluidizedbed reactor through the bottom mixing chamber below the distributorplate, the carbon black is heated and purged simultaneously in a purgevessel to remove absorbed water and oxygen which are poison for thecatalyst. Typically, the carbon black is heated at about 150° C. bysteam coils installed at the outer surface of the vessel and insulated.At the same time, the carbon black is slowly purged with nitrogen for atleast 4 hours. Since a large inventory of the purged carbon black isneeded to continuously operate the reactor for a long period of time,purging is done in a batch mode in a large vessel. This vessel has atotal volume of about 30 ft³ (2 feet in diameter and about 10 feet inheight) and typically handles about 250 pounds of the carbon black pereach batch operation. Two identical vessels are typically employed intandem: i.e., while one vessel is being emptied out to feed the purgedcarbon black into the reactor, the other one is being heated and purged.

A vanadium based catalyst is employed with triisobutylaluminum (TIBA)and chloroform (CHCl₃) as the cocatalyst and promoter, respectively.Since only a small amount of such cocatalyst and promoter is needed forthe polymerization reaction, a 10% (by weight) solution with isopentaneis made and fed into the reactor to facilitate the control of the feedrate. The feed rate ranges of TIBA and CHCl₃ solutions are 600 to 700cc/hr and 300 to 400 cc/hr, respectively.

The reactor total pressure is maintained at about 300 psi, while thepartial pressure of ethylene is maintained at about 100 psi. When thereactor operation reaches a steady state, the values of C₃ /C₂ and H₂/C₂, all molar ratios, are maintained at 1.3 to 1.7 and 0.002 to 0.004,respectively. Hydrogen is used to control the melt index of the product,more specifically to control its Mooney viscosity. ENB(5-ethylidene-2-norbornene) is used as diene. At steady state of thereactor operation, the typical feed rate of ENB is 200 to 240 cc/hr. Therest of the gas composition is nitrogen.

The reactor is operated by feeding the carbon black at a rate of about900 to 1,100 g/hr. Carbon black incorporated EPDM granular resin isproduced at the rate of 6 to 9 lb/hr without encountering any seriousreactor operational problems. Typical samples have the followingproperties:

    ______________________________________                                        Propylene content =    44.2% by weight                                        ENB incorporation =     5.2% by weight                                        Mooney viscosity =     30                                                     Carbon black content = 35% by weight                                          Average particle size of the resin =                                                                  0.052 inches                                                                 (1.321 mm).                                            ______________________________________                                    

To determine the critical carbon black content in the product at aboutthe same production rate, the feed rate of the carbon black is graduallyreduced. This critical carbon black content is the value above which thefluidized bed reactor produces granular resin without having anyexcessive agglomeration of resin and reactor operational problems, butbelow which small agglomerates start to form in the reactor and beingdischarged with granular resin through the product discharge valve andproduct discharge tank. If the reactor were operated below the criticalcarbon black content for a certain period of time, fluidizaton wouldcease resulting in a channelling flow and subsequently requiring areactor shut-down. When the carbon black feed rate is reduced to about750 g/hr, small agglomerates start to form in the reactor which aredischarged with granular resin through the product discharge valve andproduct discharge tank. A typical sample is analyzed to referencing thefollowing properties:

    ______________________________________                                        Propylene content =    47% by weight                                          ENB incorporation =     5.6% by weight                                        Mooney viscosity =     35                                                     Carbon black content = 30% by weight                                          Average particle size of the resin =                                                                  0.072 inches                                                                 (1.829 mm).                                            ______________________________________                                    

EXAMPLE 12 Production of EPDM with N-650 Carbon Black Treated withOM-PDMS-A

The same N-650 carbon black as in Example 11 is treated with theOM-PDMS-A. Since the treatment method shown in Example 2 is notpractical to treat a large amount of carbon black, the followingtreatment method is preferred and used.

Typical carbon black producers use liquid binders to make carbon blackbeads out of carbon black powder in a wet-beading process. This beadingprocess is to increase the bulk density of the carbon black for ease ofhandling and shipping. A typical liquid binder is a water solution of abinding agent selected from either corn syrup, lignin sulfonates, ormolasses. The wet beads are then dried in a rotary kiln at a typicaltemperature of about 500° F., where the water evaporates and the bindingagent is carbonized.

The treatment of the carbon black with the OM-PDMS-A is done by usingthese wet-beading and drying processes. This time, an emulsion of theOM-PDMS-A is used as the liquid binder to make beads. The emulsioncontains about 35% by weight of the OM-PDMS-A. The carbon black beadsare dried in the rotary kiln, and subsequently pulverized using a hammermill to make the powder treated with the OM-PDMS-A. In the wet-beadingprocess, the amount of OM-PDMS-A emulsion is controlled in a way thatthe treated carbon black contains about 10% of OM-PDMS-A by weight.Before this treated carbon black powder is introduced into the fluidizedbed reactor, this material is heated and purged in the same vessel withthe same procedures as in Example 11.

Utilizing the same reactor and with the same catalyst, cocatalyst,promoter, diene, C₃ /C₂ and H₂ /C₂ molar ratios, superficial gasvelocity, and reactor temperature described in Example 11, an attempt ismade to produce the same EPDM granular resin as in Example 11. Thetreated carbon black powder is fed at a rate of about 800 to 1,000 g/hr.The feed rates of cocatalyst and promoter solutions are about 600 to 700cc/hr and 300 to 400 cc/hr, respectively. ENB is fed at a rate of 200 to240 cc/hr. The reactor runs well producing a carbon black incorporatedEPDM granular resin at a rate of 7 to 10 lb/hr. Typical samples have thefollowing properties:

    ______________________________________                                        Propylene content =    44.0% by weight                                        ENB incorporation =     5.1% by weight                                        Mooney viscosity =     32                                                     Carbon black content = 27% by weight                                          Average particle size of the resin =                                                                  0.045 inches                                                                 (1.143 mm).                                            ______________________________________                                    

Following the same procedure described in Example 11, the criticalcarbon black content in the product is determined. A typical sample ofinitial agglomerates is analyzed to reveal the following properties:

    ______________________________________                                        Propylene content =    45.8% by weight                                        ENB incorporation =     5.4% by weight                                        Mooney viscosity =     34                                                     Carbon black content = 23% by weight                                          Average particle size of the resin =                                                                  0.070 inches                                                                 (1.778 mm).                                            ______________________________________                                    

When this critical carbon black content in this example is compared withthat in Example 11, a smaller amount of the treated carbon black (byabout 23% by weight) is needed to produce about the same EPDM productsat about the same reactor operating conditions. Therefore, thesynergistic effect of the OM-PDMS-A on an inert particulate material isalso clearly seen in a fluidized bed reactor.

What is claimed is:
 1. A process for preventing agglomeration of stickypolymers in a polymerization system which comprises adding to saidpolymerization system about 0.3 to about 80 weight percent based on theweight of the final product of an inert particulate material having asurface coating thereon of an organo modified polydimethylsiloxane(OM-PDMS) of the formula: ##STR3## wherein: R, may be the same ordifferent, and represents phenyl or an alkyl group having from 1 to 4carbon atoms;R', represents hydrogen, or a straight or branched orcyclic alkyl chain having 5 to 50 carbon atoms; R", may be the same ordifferent and represents R or R' R"' is alkylene, cycloalkyl, or alkoxywhich can be substituted with hydroxy, amino, alkyl substituted amino,hydroxyl amino, phenol, alkyl substituted phenol, alkyl substitutedpiperidinoxy and epoxy; X=is an integer of 0 to <2000 Y=is an integer of0 to <2000, Z is an integer of 1 to 2000, with the proviso that the sumof (x+y+z) is greater than or equal to 4 and less than or equal to 2000,with the further proviso that the repeat units if they are present canbe in any sequence, either random or non-random.
 2. A process forpreventing agglomeration of sticky polymers in a fluidized bed whichcomprises adding to said fluidized bed about 0.3 to about 80 weightpercent based on the weight of the final product of an inert particulatematerial having a surface coating thereon of a OM-PDMS of the formula.##STR4## wherein R, may be the same or different, and represents phenylor an alkyl group having from 1 to 4 carbon atoms;R', representshydrogen, or a straight or branched or cyclic alkyl chain having 5 to 50carbon atoms; R", may be the same or different and represents R or R'R"' is alkylene, cycloalkyl, or alkoxy which can be substituted withhydroxy, amino, alkyl substituted amino, hydroxyl amino, phenol, alkylsubstituted phenol, alkyl substituted piperidinoxy and epoxy; X=is aninteger of 0 to <2000 Y=is an integer of 0 to <2000, Z is an integer of1 to 2000, with the proviso that the sum of (x+y+z) is greater than orequal to 4 and less than or equal to 2000, with the further proviso thatthe repeat units if they are present can be in any sequence, eitherrandom or non-random.
 3. A process according to claim 1 wherein saidpolymerization system includes a stirred reactor.
 4. A process accordingto claim 1 wherein said coating is present on said inert particulatematerial in an amount of about 0.02% to about 20% based on the weight ofsaid inert particulate material.
 5. A process according to claim 1wherein said coating is present on said inert particulate material in anamount of about 1% to about 10% based on the weight of said inertparticulate material.
 6. A process according to claim 1 wherein saidinert particulate material having said organo-modifiedpolydimethylsiloxane coating thereon is selected from the groupconsisting of carbon black, silica, talc, and clay.
 7. A processaccording to claim 1 wherein said inert particulate material is carbonblack having a primary particle size of about 1 to about 100 nanometers,an average size of aggregate of about 0.01 to about 10 microns, aspecific surface area of about 30 to about 1,500 m² /gm and adibutylphthalate absorption of about 10 to about 700 cc/100 grams.
 8. Aprocess according to claim 1 wherein said inert particulate material isamorphous silica having a primary particle size of about 5 to 50nanometers, an average size of aggregate of about 0.1 to about 10microns, a specific surface area of about 50 to about 500 m² /gm and adibutylphthalate absorption of about 100 to 400 cc/100 grams.
 9. Aprocess according to claim 1 wherein said inert particulate material isnon-aggregated silica, or talc, or clay, having an average particle sizeof about 0.01 to about 10 microns, a specific surface area of about 2 to350 m² /gm and an oil absorption of about 20 to about 300 gm per 100 gm.10. A process according to claim 1 wherein said sticky polymers are:a.ethylene propylene rubbers; b. ethylene propylene diene termonomerrubbers; c. polybutadiene rubbers; and d. high ethylene contentpropylene ethylene block copolymers; e. essentially amorphous orelastomeric polypropylenes; f. ethylene/butene, ethylene hexane,ethylene/propylene butylene, ethylene/propylene/hexane andethylene/butene/hexene polymers.
 11. A process according to claim 10wherein said ethylene/propylene/diene termonomers areethylene/propylene/ethylidenenorbornene termonomers.
 12. A processaccording to claim 10 wherein said ethylene propylene diene termonomersare ethylene/propylene/hexadiene termonomers.
 13. A process according toclaim 7 wherein said carbon black is employed in an amount of about 0.3%to about 70% based on the weight of the final polymer product.
 14. Aprocess according to claim 7 wherein said carbon black is employed in anamount of about 5% to 65% based on the weight of the final product. 15.A process according to claim 8 wherein said amorphous silica is employedin an amount of about 0.3% to about 70% based on the weight of the finalproduct.
 16. A process according to claim 8 wherein said amorphoussilica is employed in an amount of about 5% to about 65% based on theweight of the final product.
 17. A process according to claim 9 whereinsaid non-aggregated silica, talc, or clay is employed in an amount ofabout 0.3% to about 80% based on the weight of the final product.
 18. Aprocess according to claim 9 wherein said non-aggregated silica, talc,or clay is employed in an amount of about 12% to about 75% based on theweight of the final product.
 19. A process according to claim 1 whereinR is methyl, R' is hydrogen and R" is methyl.
 20. A process forpreventing agglomeration of ethylene propylene ethylidenenorborneneterpolymers produced in a fluidized bed reactor catalyzed by atransition metal catalyst, which comprises conducting saidpolymerization reaction in the presence of about 0.3 to about 70 weightpercent, based on the weight of the final product of carbon black havinga primary particle size of about 1 to about 100 nanometers, an averagesize of aggregate of about 0.01 to about 10 microns, a specific surfacearea of about 30 to about 1,500 m² /gm, and a dibutylphthalateabsorption of about 10 to about 700 cc/100 grams, said carbon blackhaving a surface coating thereon of an organo modifiedpolydimethylsiloxane of the formula: ##STR5## wherein: R, may be thesame or different, and represents phenyl or an alkyl group having from 1to 4 carbon atoms;R', represents hydrogen, or a straight or branched orcyclic alkyl chain having 5 to 50 carbon atoms; R", may be the same ordifferent and represents R or R' R"' is alkylene, cycloalkyl or alkoxywhich can be substituted with hydroxy, amino, alkyl substituted amino,hydroxyl amino, phenol, alkyl substituted phenol, alkyl substitutedpiperidinoxy and epoxy; X=is an integer of 0 to <2000 Y=is an integer of0 to <2000, Z is an integer of 1 to 2000, with the proviso that the sumof (x+y+z) is greater than or equal to 4 and less than or equal to 2000,with the further proviso that the repeat units if they are present canbe in any sequence, either random or non-random.
 21. A process accordingto claim 20 wherein said carbon black is employed in an amount of about5% to about 65% based on the weight of the final product.
 22. A processaccording to claim 20 wherein said carbon black is heated and purgedwith nitrogen prior to entry in said reactor.
 23. A process according toclaim 20 wherein said surface coating is present in said carbon black inan amount of about 0.02% to about 20% based on the weight of said carbonblack.